最强的 C# Autofac学习笔记

Posted 2022-03-28 *心简单，世界也会变的简单*

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一、为什么使用Autofac?

Autofac是.NET领域最为流行的IoC框架之一，传说是速度最快的一个。

1.1、性能

有人专门做了测试：

1.2、优点

1）与C#语言联系很紧密。C#里的很多编程方式都可以为Autofac使用，例如可以使用Lambda表达式注册组件。

2）较低的学习曲线。学习它非常的简单，只要你理解了IoC和DI的概念以及在何时需要使用它们。

3）支持JSON/XML配置。

4）自动装配。

5）与Asp.Net MVC集成。

6）微软的Orchad开源程序使用的就是Autofac，可以看出它的方便和强大。

1.3、资源

官方网站：http://autofac.org/

GitHub网址：https://github.com/autofac/Autofac

学习资料：Autofac中文文档

二、数据准备 2.1、新建项目

IService下的接口类：

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

namespaceLinkTo.Test.Autofac.IService

///<summary>

///动物吠声接口类

///</summary>

publicinterfaceIAnimalBark

///<summary>

///吠叫

///</summary>

voidBark;

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

namespaceLinkTo.Test.Autofac.IService

///<summary>

///动物睡眠接口类

///</summary>

publicinterfaceIAnimalSleep

///<summary>

///睡眠

///</summary>

voidSleep;

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

namespaceLinkTo.Test.Autofac.IService

///<summary>

///学校接口类

///</summary>

publicinterfaceISchool

///<summary>

///放学

///</summary>

voidLeaveSchool;

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

namespaceLinkTo.Test.Autofac.IService

///<summary>

///学生接口类

///</summary>

publicinterfaceIStudent

///<summary>

///增加学生

///</summary>

///<param name="studentID">学生ID</param>

///<param name="studentName">学生姓名</param>

voidAdd( stringstudentID, stringstudentName);

Service下的接口实现类：

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingLinkTo.Test.Autofac.IService;

namespaceLinkTo.Test.Autofac.Service

///<summary>

///猫类

///</summary>

publicclassCat : IAnimalSleep

///<summary>

///睡眠

///</summary>

publicvoidSleep

Console.WriteLine( "小猫咪睡着了zZ");

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingLinkTo.Test.Autofac.IService;

namespaceLinkTo.Test.Autofac.Service

///<summary>

///狗类

///</summary>

publicclassDog : IAnimalBark, IAnimalSleep

///<summary>

///吠叫

///</summary>

publicvoidBark

Console.WriteLine( "汪汪汪");

///<summary>

///睡眠

///</summary>

publicvoidSleep

Console.WriteLine( "小狗狗睡着了zZ");

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingLinkTo.Test.Autofac.IService;

namespaceLinkTo.Test.Autofac.Service

///<summary>

///学校类

///</summary>

publicclassSchool : ISchool

///<summary>

///IAnimalBark属性

///</summary>

publicIAnimalBark AnimalBark get; set;

///<summary>

///放学

///</summary>

publicvoidLeaveSchool

AnimalBark.Bark;

Console.WriteLine( "你家的熊孩子放学了⊙o⊙");

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingLinkTo.Test.Autofac.IService;

namespaceLinkTo.Test.Autofac.Service

///<summary>

///学生类

///</summary>

publicclassStudent : IStudent

///<summary>

///无参构造函数

///</summary>

publicStudent

///<summary>

///有参构造函数

///</summary>

///<param name="studentID">学生ID</param>

///<param name="studentName">学生姓名</param>

publicStudent( stringstudentID, stringstudentName)

Add(studentID, studentName);

///<summary>

///增加学生

///</summary>

///<param name="studentID">学生ID</param>

///<param name="studentName">学生姓名</param>

publicvoidAdd( stringstudentID, stringstudentName)

Console.WriteLine($ "新增的学生是：studentName");

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading;

usingSystem.Threading.Tasks;

usingLinkTo.Test.Autofac.IService;

namespaceLinkTo.Test.Autofac.Service

///<summary>

///动物摇尾巴

///</summary>

publicclassAnimalWagging

///<summary>

///IAnimalBark属性

///</summary>

IAnimalBark animalBark;

///<summary>

///有参构造函数

///</summary>

///<param name="bark">IAnimalBark变量</param>

publicAnimalWagging(IAnimalBark bark)

animalBark = bark;

///<summary>

///摇尾巴

///</summary>

publicvirtualvoidWagging

animalBark.Bark;

Console.WriteLine( "摇尾巴");

///<summary>

///计数

///</summary>

///<returns></returns>

publicstaticintCount

return6;

///<summary>

///任务

///</summary>

///<param name="name">动物名称</param>

///<returns></returns>

publicvirtualasyncTask< string> WaggingAsync( stringname)

varresult = awaitTask.Run( => Count);

return$ "name摇了result下尾巴";

2.2、Autofac安装

Client项目右键->管理 NuGet 程序包->Autofac。

三、IoC-注册 3.1、类型注册

a）类型注册：使用RegisterType进行注册。

//注册Autofac组件

ContainerBuilder builder = newContainerBuilder;

//注册实现类Student，当我们请求IStudent接口的时候，返回的是类Student的对象。

builder.RegisterType<Student>.As<IStudent> ;

//上面这句也可改成下面这句，这样请求Student实现了的任何接口的时候，都会返回Student对象。

//builder.RegisterType<Student>.AsImplementedInterfaces;

IContainer container = builder.Build;

//请求IStudent接口

IStudent student = container.Resolve<IStudent> ;

student.Add( "1001", "Hello");

b）类型注册(别名)：假如一个接口有多个实现类，可以在注册时起别名。

ContainerBuilder builder = newContainerBuilder;

builder.RegisterType <Dog>.Named<IAnimalSleep>( "Dog");

builder.RegisterType <Cat>.Named<IAnimalSleep>( "Cat");

IContainer container = builder.Build;

vardog = container.ResolveNamed<IAnimalSleep>( "Dog");

dog.Sleep;

varcat = container.ResolveNamed<IAnimalSleep>( "Cat");

cat.Sleep;

c）类型注册(枚举)：假如一个接口有多个实现类，也可以使用枚举的方式注册。

publicenumAnimalType

Dog,

Cat

ContainerBuilder builder = newContainerBuilder;

builder.RegisterType <Dog>.Keyed<IAnimalSleep> (AnimalType.Dog);

builder.RegisterType <Cat>.Keyed<IAnimalSleep> (AnimalType.Cat);

IContainer container = builder.Build;

vardog = container.ResolveKeyed<IAnimalSleep> (AnimalType.Dog);

dog.Sleep;

varcat = container.ResolveKeyed<IAnimalSleep> (AnimalType.Cat);

cat.Sleep;

3.2、实例注册 ContainerBuilder builder = newContainerBuilder;

builder.RegisterInstance <IStudent>( newStudent);

IContainer container = builder.Build;

IStudent student = container.Resolve<IStudent> ;

student.Add( "1001", "Hello"); 3.3、Lambda注册

a）Lambda注册

ContainerBuilder builder = newContainerBuilder;

builder.Register(c => newStudent).As<IStudent> ;

IContainer container = builder.Build;

IStudent student = container.Resolve<IStudent> ;

student.Add( "1001", "Hello");

b）Lambda注册(NamedParameter)

ContainerBuilder builder = newContainerBuilder;

builder.Register <IAnimalSleep>((c, p) =>

vartype = p.Named< string>( "type");

if(type == "Dog")

returnnewDog;

else

returnnewCat;

).As <IAnimalSleep> ;

IContainer container = builder.Build;

vardog = container.Resolve<IAnimalSleep>( newNamedParameter( "type", "Dog"));

dog.Sleep;

3.4、程序集注册

如果有很多接口及实现类，假如觉得这种一一注册很麻烦的话，可以一次性全部注册，当然也可以加筛选条件。

ContainerBuilder builder = newContainerBuilder;

Assembly assembly = Assembly.Load( "LinkTo.Test.Autofac.Service"); //实现类所在的程序集名称

builder.RegisterAssemblyTypes(assembly).AsImplementedInterfaces; //常用

//builder.RegisterAssemblyTypes(assembly).Where(t=>t.Name.StartsWith("S")).AsImplementedInterfaces; //带筛选

//builder.RegisterAssemblyTypes(assembly).Except<School>.AsImplementedInterfaces; //带筛选

IContainer container = builder.Build;

//单实现类的用法

IStudent student = container.Resolve<IStudent> ;

student.Add( "1001", "Hello");

//多实现类的用法

IEnumerable<IAnimalSleep> animals = container.Resolve<IEnumerable<IAnimalSleep>> ;

foreach( varitem inanimals)

item.Sleep;

3.5、泛型注册 ContainerBuilder builder = newContainerBuilder;

builder.RegisterGeneric( typeof(List<>)).As( typeof(IList<> ));

IContainer container = builder.Build;

IList < string> list = container.Resolve<IList< string>>; 3.6、默认注册

ContainerBuilder builder = newContainerBuilder;

//对于同一个接口，后面注册的实现会覆盖之前的实现。

//如果不想覆盖的话，可以用PreserveExistingDefaults，这样会保留原来注册的实现。

builder.RegisterType<Dog>.As<IAnimalSleep> ;

builder.RegisterType <Cat>.As<IAnimalSleep>.PreserveExistingDefaults; //指定为非默认值

IContainer container = builder.Build;

vardog = container.Resolve<IAnimalSleep> ;

dog.Sleep;

四、IoC-注入 4.1、构造函数注入

ContainerBuilder builder = newContainerBuilder;

builder.RegisterType <AnimalWagging> ;

builder.RegisterType <Dog>.As<IAnimalBark> ;

IContainer container = builder.Build;

AnimalWagging animal = container.Resolve<AnimalWagging> ;

animal.Wagging;

4.2、属性注入

ContainerBuilder builder = newContainerBuilder;

Assembly assembly = Assembly.Load( "LinkTo.Test.Autofac.Service"); //实现类所在的程序集名称

builder.RegisterAssemblyTypes(assembly).AsImplementedInterfaces.PropertiesAutowired; //常用

IContainer container = builder.Build;

ISchool school = container.Resolve<ISchool> ;

school.LeaveSchool;

五、IoC-事件

Autofac在组件生命周期的不同阶段，共对应了5个事件，执行顺序如下所示：

1.OnRegistered->2.OnPreparing->3.OnActivating->4.OnActivated->5.OnRelease

ContainerBuilder builder = newContainerBuilder;

builder.RegisterType <Student>.As<IStudent>

.OnRegistered(e => Console.WriteLine( "OnRegistered：在注册的时候调用"))

.OnPreparing(e => Console.WriteLine( "OnPreparing：在准备创建的时候调用"))

.OnActivating(e => Console.WriteLine( "OnActivating：在创建之前调用"))

//.OnActivating(e => e.ReplaceInstance(new Student("1000", "Test")))

.OnActivated(e => Console.WriteLine( "OnActivated：在创建之后调用"))

.OnRelease(e => Console.WriteLine( "OnRelease：在释放占用的资源之前调用"));

using(IContainer container = builder.Build)

IStudent student = container.Resolve<IStudent> ;

student.Add( "1001", "Hello");

六、IoC-生命周期 6.1、Per Dependency

Per Dependency：为默认的生命周期，也被称为"transient"或"factory"，其实就是每次请求都创建一个新的对象。

ContainerBuilder builder = newContainerBuilder;

Assembly assembly = Assembly.Load( "LinkTo.Test.Autofac.Service"); //实现类所在的程序集名称

builder.RegisterAssemblyTypes(assembly).AsImplementedInterfaces.PropertiesAutowired.InstancePerDependency; //常用

IContainer container = builder.Build;

ISchool school1 = container.Resolve<ISchool> ;

ISchool school2 = container.Resolve<ISchool> ;

Console.WriteLine(school1.Equals(school2));

6.2、Single Instance

Single Instance：就是每次都用同一个对象。

ContainerBuilder builder = newContainerBuilder;

Assembly assembly = Assembly.Load( "LinkTo.Test.Autofac.Service"); //实现类所在的程序集名称

builder.RegisterAssemblyTypes(assembly).AsImplementedInterfaces.PropertiesAutowired.SingleInstance; //常用

IContainer container = builder.Build;

ISchool school1 = container.Resolve<ISchool> ;

ISchool school2 = container.Resolve<ISchool> ;

Console.WriteLine(ReferenceEquals(school1, school2));

6.3、Per Lifetime Scope

Per Lifetime Scope：同一个Lifetime生成的对象是同一个实例。

ContainerBuilder builder = newContainerBuilder;

builder.RegisterType <School>.As<ISchool> .InstancePerLifetimeScope;

IContainer container = builder.Build;

ISchool school1 = container.Resolve<ISchool> ;

ISchool school2 = container.Resolve<ISchool> ;

Console.WriteLine(school1.Equals(school2));

using(ILifetimeScope lifetime = container.BeginLifetimeScope)

ISchool school3 = lifetime.Resolve<ISchool> ;

ISchool school4 = lifetime.Resolve<ISchool> ;

Console.WriteLine(school3.Equals(school4));

Console.WriteLine(school2.Equals(school3));

七、IoC-通过配置文件使用Autofac 7.1、组件安装

Client项目右键->管理 NuGet 程序包->Autofac.Configuration及Microsoft.Extensions.Configuration.Xml。

7.2、配置文件

新建一个AutofacConfigIoC.xml文件，在其属性的复制到输出目录项下选择始终复制。

<?xml version="1.0" encoding="utf-8" ?>

<type>LinkTo.Test.Autofac.Service.Student, LinkTo.Test.Autofac.Service </type>

</components>

<type>LinkTo.Test.Autofac.Service.Dog, LinkTo.Test.Autofac.Service </type>

</components>

<type>LinkTo.Test.Autofac.Service.AnimalWagging, LinkTo.Test.Autofac.Service </type>

</components>

<type>LinkTo.Test.Autofac.Service.School, LinkTo.Test.Autofac.Service </type>

</components>

</autofac>

7.3、测试代码

//加载配置

ContainerBuilder builder = newContainerBuilder;

varconfig = newConfigurationBuilder;

config.AddXmlFile( "AutofacConfigIoC.xml");

varmodule = newConfigurationModule(config.Build);

builder.RegisterModule(module);

IContainer container = builder.Build;

//无注入测试

IStudent student = container.Resolve<IStudent> ;

student.Add( "1002", "World");

//构造函数注入测试

AnimalWagging animal = container.Resolve<AnimalWagging> ;

animal.Wagging;

//属性注入测试

ISchool school = container.Resolve<ISchool> ;

school.LeaveSchool;

八、AOP 8.1、组件安装

Client项目右键->管理 NuGet 程序包->Autofac.Extras.DynamicProxy。

8.2、拉截器

usingSystem;

usingSystem.Collections.Generic;

usingSystem.IO;

usingSystem.Linq;

usingSystem.Reflection;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingCastle.DynamicProxy;

namespaceLinkTo.Test.Autofac.Client

///<summary>

///拦截器：需实现IInterceptor接口。

///</summary>

publicclassCallLogger : IInterceptor

privatereadonlyTextWriter _output;

publicCallLogger(TextWriter output)

_output = output;

///<summary>

///拦截方法：打印被拦截的方法--执行前的名称、参数以及执行后的返回结果。

///</summary>

///<param name="invocation">被拦截方法的信息</param>

publicvoidIntercept(IInvocation invocation)

//空白行

_output.WriteLine;

//在下一个拦截器或目标方法处理之前的处理

_output.WriteLine($ "调用方法：invocation.Method.Name");

if(invocation.Arguments.Length > 0)

_output.WriteLine($ "参数：string.Join(", ", invocation.Arguments.Select(a => (a ?? "").ToString).ToArray)");

//调用下一个拦截器(若存在)，直到最终的目标方法(Target Method)。

invocation.Proceed;

//获取被代理方法的返回类型

varreturnType = invocation.Method.ReturnType;

//异步方法

if(IsAsyncMethod(invocation.Method))

//Task：返回值是固定类型

if(returnType != null&& returnType == typeof(Task))

//定义一个异步方法来等待目标方法返回的Task

asyncTask Continuation => await(Task)invocation.ReturnValue;

//Continuation中并没有使用await，所以Continuation就如同步方法一样是阻塞的。

invocation.ReturnValue = Continuation;

//Task<T>：返回值是泛型类型

else

//获取被代理方法的返回类型

varreturnTypeT = invocation.Method.ReflectedType;

if(returnTypeT != null)

//获取泛型参数集合，集合中的第一个元素等价于typeof(Class)。

varresultType = invocation.Method.ReturnType.GetGenericArguments[ 0];

//利用反射获得等待返回值的异步方法

MethodInfo methodInfo = typeof(CallLogger).GetMethod( "HandleAsync", BindingFlags.Public | BindingFlags.Instance);

//调用methodInfo类的MakeGenericMethod方法，用获得的类型T(<resultType>)来重新构造HandleAsync方法。

varmi = methodInfo.MakeGenericMethod(resultType);

//Invoke：使用指定参数调用由当前实例表示的方法或构造函数。

invocation.ReturnValue = mi.Invoke( this, new[] invocation.ReturnValue );

vartype = invocation.Method.ReturnType;

varresultProperty = type.GetProperty( "Result");

if(resultProperty != null)

_output.WriteLine($ "方法结果：resultProperty.GetValue(invocation.ReturnValue)");

//同步方法

else

if(returnType != null&& returnType != typeof( void))

_output.WriteLine($ "方法结果：invocation.ReturnValue");

///<summary>

///判断是否异步方法

///</summary>

publicstaticboolIsAsyncMethod(MethodInfo method)

return

(

method.ReturnType == typeof(Task) ||

(method.ReturnType.IsGenericType && method.ReturnType.GetGenericTypeDefinition == typeof(Task<> ))

);

///<summary>

///构造等待返回值的异步方法

///</summary>

///<typeparam name="T"></typeparam>

///<param name="task"></param>

///<returns></returns>

publicasyncTask<T> HandleAsync<T>(Task<T> task)

vart = awaittask;

returnt;

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingCastle.DynamicProxy;

namespaceLinkTo.Test.Autofac.Client

publicclassCallTester: IInterceptor

publicvoidIntercept(IInvocation invocation)

Console.WriteLine( "啥也不干");

invocation.Proceed;

Console.WriteLine( "也不干啥");

8.3、测试代码

注意：对于以类方式的注入，Autofac Interceptor要求类的方法必须为virtual方法。如AnimalWagging类的Wagging、WaggingAsync(string name)都加了virtual修饰符。

ContainerBuilder builder = newContainerBuilder;

//注册拦截器

builder.Register(c => newCallLogger(Console.Out));

builder.Register(c => newCallTester);

//动态注入拦截器

//这里定义了两个拦截器，注意它们的顺序。

builder.RegisterType<Student>.As<IStudent>.InterceptedBy( typeof(CallLogger), typeof(CallTester)).EnableInterfaceInterceptors;

//这里定义了一个拦截器

builder.RegisterType<AnimalWagging>.InterceptedBy( typeof(CallLogger)).EnableClassInterceptors;

builder.RegisterType <Dog>.As<IAnimalBark> ;

IContainer container = builder.Build;

IStudent student = container.Resolve<IStudent> ;

student.Add( "1003", "Kobe");

AnimalWagging animal = container.Resolve<AnimalWagging> ;

animal.Wagging;

Task < string> task = animal.WaggingAsync( "哈士奇");

Console.WriteLine($ "task.Result");

IoC参考自：

https://www.xin3721.com/ArticlecSharp/c14013.html

http://niuyi.github.io/blog/2012/04/06/autofac-by-unit-test/

AOP参考自：

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